disclaimer: i'm not gonna say any of these are "replacements for" or "alternatives to" whatever you use on windows. these are just decent bits of software that i use in my life!
worth noting that firefox, krita, aseprite, tenacity/audacity, VLC*, OBS, and libreoffice are all my software of choice on windows as well. and steam of course is unavoidable. blender is my 3d software of choice (on windows and linux) and for game dev, godot and unreal engine both work in linux too (yes, unreal has an editor for linux, but it lags behind main and isn't tested and you have to build it yourself so YMMV).
* i've recently switched from vlc to mpv as my media player of choice (which also works on windows and linux) but vlc is good too
my music player/library browser of choice is foobar2000. i don't love some things about it, and it's closed source, but i've yet to find an alternative that does everything i want it to (i'm very picky). it's windows only but it runs perfectly on WINE so i use it in linuxland too.
